Plato is well aware that 4536 is not a probability. You weren't given the final answer, you were given some help on how to get the final answer. You are expected to think about the hint and then try and get the final answer yourself. If you are still stuck, you show what you could do and you say where you are stuck.

This is said with absolutely no disrespect intended: just the truth.
You have absolutely no idea what is going in with this question.
Your profound misunderstanding cannot be addressed in a forum such as this.
Please seek out a sit-down with a live tutor.